Photographic film has the characteristic that its spectral sensitivity distribution is such that the film is substantially insensitive to light having frequencies within certain narrow regions of the visible spectrum in contrast to the spectral sensitivity distribution of the human eye which is relatively sensitive to visible light in such narrow regions. Illumination by the use of lamps which emit light only in such narrow regions may therefore be employed during the manufacture and process of such film without damage thereto. Lamp fixtures which provide such narrow band illumination are often called "safe-lights" by those in the photographic industry.